Remove legacy cloud-init template

The user-data.yml.tftpl file was replaced with OS-specific templates to
support
different init systems. The new templates are
user-data-systemd.yml.tftpl and
user-data-alpine.yml.tftpl, selected based on the VM's OS type.

cloud-init/user-data.yml.tftpl

@@ -1,32 +0,0 @@
-#cloud-config
-
-# 1. Configuration du nom d'hôte de la machine
-hostname: ${hostname}
-fqdn: ${hostname}
-preserve_hostname: false
-
-# 2. Création de l'utilisateur
-users:
-  - name: ${username}
-    sudo: ALL=(ALL) NOPASSWD:ALL
-    groups: sudo, admin
-    shell: /bin/bash
-    ssh_authorized_keys:
-      - ${ssh_key}
-
-# 3. Mise à jour du système
-package_update: true
-package_upgrade: true
-
-# 4. Installation des paquets
-packages:
-  - qemu-guest-agent
-  - curl
-
-# 5. Installation et configuration de Tailscale
-runcmd:
-  # Enable and start qemu-guest-agent (systemd)
-  - [ systemctl, enable, qemu-guest-agent, --now ]
-  # Install and configure Tailscale
-  - [ sh, -c, "curl -fsSL https://tailscale.com/install.sh | sh" ]
-  - [ tailscale, up, --authkey=${tailscale_auth_key}, --hostname=${vm_name} ]